Effect of shear displacement on the aperture and permeability of a rock fracture
Effect of shear displacement on the aperture and permeability of a rock fracture
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DOI：
10.1016/s0148-9062(98)00165-x
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发表时间：
1998-12-01
影响因子：
7.2
通讯作者：
Zimmerman, RW
中科院分区：
文献类型：
--
作者：
Yeo, IW;De Freitas, MH;Zimmerman, RW
本文报道了在一个粗糙孔中径向和单向流动的实验结果，并与数值计算结果进行了比较。天然砂岩裂缝的孔径复制品，在0，1和2毫米的剪切位移使用硅橡胶，再现性优于2%。实验的安排允许剪切位移，以获得不造成损害的两个位移的表面，从而保持其原始的（和基本上匹配）的几何形状。随着剪切位移的增加，接触点的数量和接触面积的分数都减小。随着剪切位移的增大，平均孔径和标准差增大，标准差与平均孔径的比值略有增大。半变异函数的研究表明，剪切位移增加的方向上垂直的粗糙度脊，孔径分布变得更加密切相关的方向paradaxed粗糙度脊比在剪切方向。流动试验表明，随着剪切位移的增加，裂缝变得不均匀和各向异性，并且在垂直于剪切位移的方向上比在平行于位移的方向上变得更具渗透性。使用雷诺方程和实际孔径分布对通过裂缝的流动进行了模拟;测得的水力孔径一般比数值测量的低约20%。(C)1998爱思唯尔科技有限公司版权所有。
The results of experiments ruing radial and unidirectional flow in a carefully described single rough aperture are reported and compared with numerical predictions. Aperture replicas of a natural sandstone fracture were made at 0, 1 and 2 mm shear displacements using silicone rubber, with a reproducibility of better than 2%. The experimental arrangement permitted shear displacement to be obtained without causing damage to the two displaced surfaces, which thus retained their original (and essentially matching) geometry. Both the number of contact points and the fractional contact area decreased with increasing shear displacement. With increasing shear displacement, mean aperture and standard deviation increased and the ratio of standard deviation to mean aperture increased slightly. Semivariogram studies indicated that as shear displacement increased in the direction normal to the roughness ridges, the aperture distribution became more closely correlated in the direction par allel to the roughness ridges than in the shear direction. Flow tests showed that,with increasing shear displacement, the fracture became heterogeneous and anisotropic and became more permeable in the direction perpendicular to the shear displacement than in the direction parallel to the displacement. Simulations were made of flow through the fracture using the Reynolds equation and the actual aperture distribution; the measured hydraulic apertures were generally about 20% lower than those measured numerically. (C) 1998 Elsevier Science Ltd. All rights reserved.